Added support for replica-read via getReplica and getReplicaMulti.

Change-Id: I1414e03ed05047a72ada629ef6558d7742a6b307
Added CNHOST and CNBUCKET environment variables.

Updated test harness so host and bucket name can be passed
via environmental variables.

Change-Id: I0f2ff103447b955e5e24828ee97dd4521fbcaef8